Zinc-Doped Mesoporous Graphitic Carbon Nitride for Colorimetric Detection of Hydrogen Peroxide

Abstract

Recently, graphitic carbon nitride (g-C 3 N 4 ) has been explored as a peroxidase-like catalyst for the nonenzymatic colorimetric detection of H 2 O 2 . In this study, we have developed a simple, low cost, and eco-friendly hydrogen bond assisted soft template method of zinc ions doping in mesoporous graphitic-carbon-nitride (Zn-mpg-C 3 N 4 ) thin nanosheets. Morphology and composition of prepared samples were determined by different characterization techniques. PEG-1500 was beneficial to enhance the porosity and surface area of g-C 3 N 4 , whereas zinc loading in the framework of g-C 3 N 4 resulted in the increase in electrical properties. The peroxidase-like catalytic activity of samples was investigated and compared based on the development of blue reaction mixture by the oxidation reaction between 3,3′,5,5′-tetramethylbenzidine and hydrogen peroxide (H 2 O 2 ) through the colorimetric method. The as-prepared 10% Zn-mpg-C 3 N 4 has shown higher peroxidase-like activity as compared to natural HRP, g-C 3 N 4 , and mpg-C 3 N 4 . This enhanced peroxidase-like activity was attributed to the thin structured nanosheets, higher specific surface area, outstanding electron transfer ability, increased band gap, and increased in charge separation of the catalyst through the direct zinc ions doping modification. The steady-state kinetics mechanism was investigated by using Michaelis− Menten kinetics, and it was found that the reaction followed a ping-pong mechanism. This outstanding catalytic activity permitted us to design a rapid and convenient colorimetric sensing method to detect H 2 O 2 . Under the optimized condition, the developed sensor exhibited a linear range of 10−2000 μM (R 2 = 0.9981), limit of detection of 1.4 μM, and limit of quantification of 3.0 μM for H 2 O 2 detection. In view of advantages compared with previous methods such as simple, facile operation, cost-effectiveness, eco-friendliness, naked eye observation, and rapid response, the developed sensor possesses huge potential and is a promising candidate for enzyme mimic sensing of H 2 O 2 in environmental and biological samples.

Porous Ag-Chitosan Nanospheres Bridged by Cysteine Residues for Colorimetric Sensing of Trace Hg2+

“…Constructing multicomponent sensing materials has become an important methodology for environmental analysis and monitoring. − It is well-known that chitosan possesses excellent mechanical properties, low toxicity, superior bioactivity, good environmental compatibility, and strong hydrogen bond interactions with target molecules. Chitosan has been regarded as a common platform to prepare some chemical or biologic sensors.…”

Solvent-free aerobic photocatalytic oxidation of alcohols to aldehydes over ZnO/C3N4

“…ascribed to the carbon atoms in C-NH 2 , while the peaks at about 288.1 eV correspond to C-NvC in the heterocyclic rings of g-C 3 N 4 . [27][28][29] In addition, the peaks of the graphitized carbon nitride framework at 286.0 and 288.1 eV in g-C 3 N 4 slightly shift to the lower binding energies of 285.8 and 287.9 eV in ZnO/C 3 N 4 -600, indicating that electrons are transferred to g-C 3 N 4 in ZnO/C 3 N 4 -600. The N 1s peaks of the g-C 3 N 4 sample are composed of four peaks at 398.3, 399.4, 400.9, and 404.1 eV (Fig.…”

“…The N 1s peaks of the g-C 3 N 4 sample are composed of four peaks at 398.3, 399.4, 400.9, and 404.1 eV (Fig. 3b), corresponding to sp 2 -hybridized nitrogen (C-NvC), tertiary nitrogen (C 3 -N), amino functional groups (NH x groups), and π-excitation, [27][28][29][30] respectively, indicating the presence of a heptazine heterocyclic structure. 30 Compared to g-C 3 N 4 , the C 1s and N 1s binding energies of ZnO/C 3 N 4 -600 show a slightly negative shift, indicating that electrons are partially transferred to the carbon atoms in the graphitized carbo nitride framework due to interaction between the g-C 3 N 4 and the composites.…”

Optical chemosensors for the gas phase detection of aldehydes: mechanism, material design, and application

“…Such change in signal can be measured when sensor molecules interact with aldehyde molecules under appropriate condition. [34][35][36] Based on different types of colorimetric signals, due to their different chemical reactions based sensing mechanisms, the sensors can be roughly divided into five categories, which include aldimine condensation based sensor, aldimine reaction mediated biomimetic nanostructure tailoring sensor, Hantzsch reaction based sensor, Sawicki reaction based sensor, and Tollens′ reaction mediated sensor. A summary and comparison about these sensing mechanisms and corresponding sensing probe materials, substrates, as well as sensing performances (selectivity, low detection limit (LDL), response time, etc.)…”